Fever is also known as hyperthermia, pyrexia, or elevated temperature. It describes a body temperature that's higher than normal. Fever can affect children and adults. A short-term increase in body temperature can help your body fight off illness.

Stridor is a high-pitched, wheezing sound caused by disrupted airflow. Airflow is usually disrupted by a blockage in the larynx (voice box) or trachea (windpipe). It's most noticeable when breathing in, though it can sometimes be heard when breath...

An airway obstruction is a blockage in any part of the airway. The airway is a complex system of tubes that conveys inhaled air from your nose and mouth into your lungs. An obstruction may partially or totally prevent air from getting into your lu...

The term "breathing difficulty" describes discomfort when breathing and the feeling that you can't draw a complete breath. This can develop gradually, or you may have a sudden onset. Breathing difficulties make you feel as though you can't get eno...

Blue lips may represent a type of cyanosis caused by a lower level of circulating oxygen in the red blood cells. It may also represent a high level of an abnormal form of hemoglobin in the circulation.

Blue fingernails may represent a type of cyanosis caused by a lower level of lack of circulating oxygen in the red blood cells. It may also represent a high level of an abnormal form of hemoglobin in the circulation.

Cyanosis refers to a bluish cast to the skin and mucous membranes caused by a lower level of circulating oxygen carried by the red blood cells. It may also represent a high level of an abnormal form of hemoglobin in the circulation.

Your intercostal muscles attach to your ribs. When you breathe in air, they normally contract and move your ribs up. At the same time, your diaphragm, which is a thin muscle that separates your chest and abdomen, drops lower and your lungs fill wi...